x86: Merge sys_sigaltstack

Change 32-bit sys_sigaltstack to PTREGSCALL2, and merge with 64-bit.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1260403316-5679-5-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/include/asm/syscalls.h

@@ -31,6 +31,9 @@ asmlinkage int sys_modify_ldt(int, void __user *, unsigned long);
 
 /* kernel/signal.c */
 long sys_rt_sigreturn(struct pt_regs *);
+long sys_sigaltstack(const stack_t __user *, stack_t __user *,
+		     struct pt_regs *);
+
 
 /* kernel/tls.c */
 asmlinkage int sys_set_thread_area(struct user_desc __user *);
@@ -46,7 +49,6 @@ int sys_clone(struct pt_regs *);
 asmlinkage int sys_sigsuspend(int, int, old_sigset_t);
 asmlinkage int sys_sigaction(int, const struct old_sigaction __user *,
 			     struct old_sigaction __user *);
-int sys_sigaltstack(struct pt_regs *);
 unsigned long sys_sigreturn(struct pt_regs *);
 
 /* kernel/sys_i386_32.c */
@@ -76,10 +78,6 @@ asmlinkage long sys_clone(unsigned long, unsigned long,
 			  struct pt_regs *);
 long sys_arch_prctl(int, unsigned long);
 
-/* kernel/signal.c */
-asmlinkage long sys_sigaltstack(const stack_t __user *, stack_t __user *,
-				struct pt_regs *);
-
 /* kernel/sys_x86_64.c */
 struct new_utsname;
 

arch/x86/kernel/entry_32.S

@@ -763,7 +763,7 @@ PTREGSCALL0(fork)
 PTREGSCALL0(clone)
 PTREGSCALL0(vfork)
 PTREGSCALL3(execve)
-PTREGSCALL0(sigaltstack)
+PTREGSCALL2(sigaltstack)
 PTREGSCALL0(sigreturn)
 PTREGSCALL0(rt_sigreturn)
 PTREGSCALL0(vm86)

arch/x86/kernel/signal.c

@@ -545,22 +545,12 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 }
 #endif /* CONFIG_X86_32 */
 
-#ifdef CONFIG_X86_32
-int sys_sigaltstack(struct pt_regs *regs)
-{
-	const stack_t __user *uss = (const stack_t __user *)regs->bx;
-	stack_t __user *uoss = (stack_t __user *)regs->cx;
-
-	return do_sigaltstack(uss, uoss, regs->sp);
-}
-#else /* !CONFIG_X86_32 */
-asmlinkage long
+long
 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
 		struct pt_regs *regs)
 {
 	return do_sigaltstack(uss, uoss, regs->sp);
 }
-#endif /* CONFIG_X86_32 */
 
 /*
  * Do a signal return; undo the signal stack.